Polyester (polyethylene terephthalate, PET) is one of the most widely used synthetic fibers globally, widely used in textiles, packaging, and plastic products. However, the accumulation of polyester waste has caused serious pressure on the environment, making efficient recycling technology an important means to solve plastic pollution and resource waste. Mechanical recycling, as the most mature and widely used method of polyester recycling in industry, converts waste polyester products into reusable materials through physical treatment, with advantages such as low cost, low energy consumption, and simple process. This article introduces the process flow of polyester mechanical recycling, including collecting, sorting, cleaning, shredding, melting, and extrusion steps, analyzes its advantages and disadvantages, and proposes feasible improvement methods. In addition, this article also compares mechanical recycling with other waste polyester treatment methods, exploring the similarities and differences in environmental impact, economic feasibility, and product quality of different methods. Through introduction and comparative analysis, this study aims to provide reference for the efficient recycling and sustainable utilization of polyester waste, and promote the development of environmental protection and circular economy.